* lisp/vc/vc.el (vc-diff-build-argument-list-internal)

(vc-version-ediff, vc-ediff): New functions.
(vc-version-diff): Use vc-diff-build-argument-list-internal.
* doc/emacs/maintaining.texi (Old Revisions): Add paragraph on new function
vc-ediff.
* etc/NEWS: Document new function `vc-ediff'.

2 files changed, 105 insertions, 93 deletions

diff --git a/doc/emacs/ChangeLog b/doc/emacs/ChangeLog
index 47aa395c730..d20c529f043 100644
--- a/doc/emacs/ChangeLog
+++ b/doc/emacs/ChangeLog
@@ -1,3 +1,8 @@
+2011-04-20  Christoph Scholtes  <cschol2112@googlemail.com>
+
+        * maintaining.texi (Old Revisions): Add paragraph on new function
+        vc-ediff.
+
 2011-03-26  Chong Yidong  <cyd@stupidchicken.com>
 
         * display.texi (Auto Scrolling): Fix scroll-up/scroll-down confusion.
@@ -22,8 +27,8 @@
 
 2011-03-09  Eli Zaretskii  <eliz@gnu.org>
 
-        * ack.texi (Acknowledgments): Convert to ISO-8859-1 encoding.  Use
-        Texinfo @-commands for non Latin-1 characters.
+        * ack.texi (Acknowledgments): Convert to ISO-8859-1 encoding.
+        Use Texinfo @-commands for non Latin-1 characters.
 
         * makefile.w32-in (MAKEINFO_OPTS): Add --enable-encoding.
 
@@ -231,8 +236,8 @@
         (Old Revisions): Document revert-buffer for vc-diff.
         (Log Buffer): Promote to a subsection.  Document header lines.
 
-        * macos.texi (Mac / GNUstep Basics): Document
-        ns-right-alternate-modifier.
+        * macos.texi (Mac / GNUstep Basics):
+        Document ns-right-alternate-modifier.
 
         * emacs.texi (Top): Update node listing.
 
@@ -553,8 +558,8 @@
         mail-self-blind, mail-default-reply-to, and mail-archive-file-name in
         favor of mail-default-headers.  Ad index entries for user-full-name and
         user-mail-address.
-        (Citing Mail): Update changes in Message mode behavior.  Document
-        mail-yank-prefix.
+        (Citing Mail): Update changes in Message mode behavior.
+        Document mail-yank-prefix.
         (Mail Signature): New node, moved from Mail Misc.
         (Mail Aliases): Mail abbrevs are the default with Message mode.
         (Mail Methods): Note that Message mode is now the default.
@@ -724,8 +729,8 @@
         * files.texi (Visiting):
         * buffers.texi (Buffers): Max buffer size is now 512 MB.
 
-        * frames.texi (Cut/Paste Other App): Document
-        save-interprogram-paste-before-kill.
+        * frames.texi (Cut/Paste Other App):
+        Document save-interprogram-paste-before-kill.
 
         * killing.texi (Kill Options): New node.
 
@@ -813,8 +818,8 @@
         * entering.texi (Exiting): C-z is now bound to suspend-frame.
 
         * custom.texi (Init Examples): Replace Rumseld with Cheny (Bug#3519).
-        (Key Bindings): Reference Init Rebinding in introductory text.  Shift
-        some of the introduction to Keymaps node.
+        (Key Bindings): Reference Init Rebinding in introductory text.
+        Shift some of the introduction to Keymaps node.
         (Keymaps): Simplify.
         (Local Keymaps): Simplify.  Move binding example to Init Rebinding.
         (Minibuffer Maps): Remove mention of Mocklisp.
@@ -1080,8 +1085,8 @@
         * misc.texi (Interactive Shell, Saving Emacs Sessions)
         (Shell History Copying, Terminal emulator): Copyedits.
 
-        * xresources.texi (Resources): Simplify descriptions.  Shorten
-        description of editres, which is not very useful these days.
+        * xresources.texi (Resources): Simplify descriptions.
+        Shorten description of editres, which is not very useful these days.
         (Table of Resources): Document fontBackend resource.
 
         * trouble.texi (Quitting): Add other undo bindings to table.
@@ -1102,8 +1107,8 @@
         (Enabling Multibyte): Remove obsolete discussion.  Copyedits.
         (Language Environments): Add language environments new to Emacs 23.
         (Multibyte Conversion): Node deleted.
-        (Coding Systems): Remove obsolete unify-8859-on-decoding-mode.  Don't
-        mention obsolete emacs-mule coding system.
+        (Coding Systems): Remove obsolete unify-8859-on-decoding-mode.
+        Don't mention obsolete emacs-mule coding system.
         (Output Coding): Copyedits.
 
         * emacs.texi (Top): Update node listing.
@@ -1159,8 +1164,8 @@
 
         * mini.texi (Completion Commands): Describe Emacs 23 completion rules.
         (Completion Options): Document read-file-name-completion-ignore-case,
-        read-buffer-completion-ignore-case, and completion-styles.  Remove
-        description of partial-completion-mode.
+        read-buffer-completion-ignore-case, and completion-styles.
+        Remove description of partial-completion-mode.
 
 2009-03-14  Glenn Morris  <rgm@gnu.org>
 
@@ -1582,8 +1587,8 @@
         * files.texi (Visiting): Document new behavior of
         confirm-nonexistent-file-or-buffer.
 
-        * buffers.texi (Select Buffer): Document
-        confirm-nonexistent-file-or-buffer.
+        * buffers.texi (Select Buffer):
+        Document confirm-nonexistent-file-or-buffer.
 
         * picture-xtra.texi (Picture Mode): Use picture-mode instead of
         edit-picture.
@@ -1708,8 +1713,8 @@
 
         * dired.texi (Dired): Mention C-x C-d too.
         (Dired Enter): Document M-n in the Dired minibuffer.
-        (Dired Navigation): Explain dired-goto-file more clearly.  Document
-        dired-isearch-filenames.
+        (Dired Navigation): Explain dired-goto-file more clearly.
+        Document dired-isearch-filenames.
         (Dired Deletion): Remove unnecessary "expunged" terminology.
         (Flagging Many Files): & is now rebound to `% &'.
         (Shell Commands in Dired): Document dired-do-async-shell-command.
@@ -1731,8 +1736,8 @@
         open-paren-in-column-0-is-defun-start more concisely.
         (Which Function, Program Indent, Info Lookup): Minor edits.
         (Basic Indent): If region is active, TAB indents the region.
-        (Multi-line Indent): If region is active, TAB indents the region.  Note
-        that indent-region is useful when Transient Mark mode is off.
+        (Multi-line Indent): If region is active, TAB indents the region.
+        Note that indent-region is useful when Transient Mark mode is off.
         (Matching): The delimiter at the cursor is highlighted---the character
         changes color.
         (Symbol Completion): Link to Completion node.
@@ -1761,12 +1766,12 @@
 
 2008-10-31  Chong Yidong  <cyd@stupidchicken.com>
 
-        * misc.texi (Document View): Renamed from Document Files, moved here
+        * misc.texi (Document View): Rename from Document Files, moved here
         from files.texi.
 
-        * files.texi (Version Control): Moved to maintaining.texi.  Subnodes
-        moved as well.
-        (Document Files): Moved to misc.texi.
+        * files.texi (Version Control): Move to maintaining.texi.
+        Subnodes moved as well.
+        (Document Files): Move to misc.texi.
 
         * maintaining.texi (Change Log): Document log-edit-insert-changelog and
         vc-update-change-log.
@@ -1782,8 +1787,8 @@
 
 2008-10-31  Chong Yidong  <cyd@stupidchicken.com>
 
-        * building.texi (Compilation Mode): Document
-        compilation-auto-jump-to-first-error.
+        * building.texi (Compilation Mode):
+        Document compilation-auto-jump-to-first-error.
         (Debuggers): Lower GUD subsections to subsubsections.
         (Starting GUD): Add cindex.
         (Lisp Interaction): Note that scratch is no longer the initial buffer.
@@ -1801,8 +1806,8 @@
 
         * emacs.texi (Top): Update node listings.
 
-        * misc.texi (Emacs Server): Rewrite.  Document daemon-mode.  Don't
-        mention obsolete emacs.bash script.
+        * misc.texi (Emacs Server): Rewrite.  Document daemon-mode.
+        Don't mention obsolete emacs.bash script.
         (Invoking emacsclient): Rewrite, moving optional arguments to
         emacsclient Options.
         (emacsclient Options): New node.  Document server-use-tcp and
@@ -1842,7 +1847,7 @@
 
 2008-10-22  Tassilo Horn  <tassilo@member.fsf.org>
 
-        * emacs.texi (Acknowledgments): Added myself to Acknowledgments
+        * emacs.texi (Acknowledgments): Add myself to Acknowledgments
         section.
 
 2008-10-21  Chong Yidong  <cyd@stupidchicken.com>
@@ -1877,15 +1882,15 @@
         crucial to using distributed version control systems.
         (Comparing Files): Note that diff uses the minibuffer, and that the
         output is shown using Diff mode.
-        (Diff Mode): Explain what "patch" and "hunk" mean.  Document
-        diff-update-on-the-fly, diff-refine-hunk, and
+        (Diff Mode): Explain what "patch" and "hunk" mean.
+        Document diff-update-on-the-fly, diff-refine-hunk, and
         diff-show-trailing-whitespaces.
         (File Archives): Add rar support.
 
         * major.texi (Choosing Modes): Make mode selection sequence more
         obvious by describing the steps in order of priority.  Note that
-        magic-mode-alist is nil by default.  Document
-        magic-fallback-mode-alist.
+        magic-mode-alist is nil by default.
+        Document magic-fallback-mode-alist.
 
 2008-10-20  Chong Yidong  <cyd@stupidchicken.com>
 
@@ -1944,8 +1949,8 @@
 2008-10-12  Chong Yidong  <cyd@stupidchicken.com>
 
         * mini.texi (Minibuffer File): Add xref to File Names.
-        (Minibuffer File): Add discussion of `~' in file names.  Add
-        insert-default-directory index reference.
+        (Minibuffer File): Add discussion of `~' in file names.
+        Add insert-default-directory index reference.
 
         * files.texi (File Names): Reorganize description.
         (Visiting): Add xref to Mode Line.  Copyedits.
@@ -1990,8 +1995,8 @@
         * msdog-xtra.texi (MS-DOS Printing, MS-DOS and MULE): No need to create
         cpNNN coding systems anymore.
         (MS-DOS and MULE): Don't mention code-pages.el.  Don't mention support
-        for unibyte mode.  Don't mention line-drawing characters.  Don't
-        mention dos-unsupported-char-glyph.
+        for unibyte mode.  Don't mention line-drawing characters.
+        Don't mention dos-unsupported-char-glyph.
 
 2008-09-25  Chong Yidong  <cyd@stupidchicken.com>
 
@@ -2022,12 +2027,12 @@
         * kmacro.texi (Basic Keyboard Macro): Make F3 and F4 the preferred
         interface for defining macros.  Simplify examples.  Note that C-g quits
         macro definitions.
-        (Keyboard Macro Counter): Document using F3 to insert counter.  Give
-        usage example.
+        (Keyboard Macro Counter): Document using F3 to insert counter.
+        Give usage example.
         (Keyboard Macro Query): Organize query responses in a table.
 
-        * fixit.texi (Fixit): Favor C-/ keybinding for undo throughout.  Link
-        to Erasing node.
+        * fixit.texi (Fixit): Favor C-/ keybinding for undo throughout.
+        Link to Erasing node.
         (Undo): Reorganize paragraphs for logical flow.  Move keybinding
         rationale to a footnote.
         (Kill Errors): Remove node, due to redundancy with Erasing.
@@ -2229,8 +2234,8 @@
         * display.texi (Visual Line Mode): New node.
 
         * basic.texi (Inserting Text): Move DEL to deletion node.
-        (Moving Point): Add additional alternative key bindings.  Describe
-        line-move-visual.
+        (Moving Point): Add additional alternative key bindings.
+        Describe line-move-visual.
         (Erasing): Describe DEL.
         (Basic Undo, Blank Lines, Arguments): Copyedit.
         (Continuation Lines): Mention Visual Line mode.
@@ -2349,8 +2354,8 @@
 
 2008-06-04  Miles Bader  <miles@gnu.org>
 
-        * display.texi (Temporary Face Changes): Add
-        `adjust-buffer-face-height'.  Rewrite description of
+        * display.texi (Temporary Face Changes):
+        Add `adjust-buffer-face-height'.  Rewrite description of
         `increase-buffer-face-height' and `decrease-default-face-height' now
         that they aren't bound by default.
 
@@ -2514,8 +2519,8 @@
         (Replace, Unconditional Replace, Other Repeating Search):
         Describe Transient Mark mode as the default.
 
-        * text.texi (Words, Pages, Fill Commands, HTML Mode): Describe
-        Transient Mark mode as the default.
+        * text.texi (Words, Pages, Fill Commands, HTML Mode):
+        Describe Transient Mark mode as the default.
         (Paragraphs): Describe how M-h behaves when region is active.
 
         * trouble.texi (Quitting): Clarify effects of C-g.
@@ -2661,8 +2666,8 @@
 
 2007-11-10  Paul Pogonyshev  <pogonyshev@gmx.net>
 
-        * search.texi (Query Replace): Mention
-        `query-replace-show-replacement'.
+        * search.texi (Query Replace):
+        Mention `query-replace-show-replacement'.
 
 2007-11-09  Nick Roberts  <nickrob@snap.net.nz>
 
@@ -3015,8 +3020,8 @@
 
 2007-04-20  David Koppelman  <koppel@ece.lsu.edu>
 
-        * display.texi (Highlight Interactively): Document
-        hi-lock-file-patterns-policy.
+        * display.texi (Highlight Interactively):
+        Document hi-lock-file-patterns-policy.
 
 2007-04-20  Martin Rudalics  <rudalics@gmx.at>
 
@@ -3574,8 +3579,8 @@
 2006-08-10  Richard Stallman  <rms@gnu.org>
 
         * text.texi (Format Faces): Substantial rewrites to deal
-        with face merging.  Empty regions don't count.  Clarify
-        face property inheritance.
+        with face merging.  Empty regions don't count.
+        Clarify face property inheritance.
 
 2006-08-08  Romain Francoise  <romain@orebokech.com>
 
@@ -4034,7 +4039,7 @@
         of emacs-xtra.texi.  Convert each @chapter into @section, @section
         into @subsection, etc.
 
-        * emacs-xtra.texi (MS-DOS): Renamed from "MS-DOG".  All references
+        * emacs-xtra.texi (MS-DOS): Rename from "MS-DOG".  All references
         updated.
 
         * msdog.texi (Microsoft Windows): Rename from "Emacs and Microsoft
@@ -4071,7 +4076,7 @@
         (Comparing Files): Delete what duplicates new node.
         (Files): Put Diff Mode in menu.
 
-        * misc.texi (Diff Mode): Moved to files.texi.
+        * misc.texi (Diff Mode): Move to files.texi.
 
         * emacs.texi (Top): Update menu for Diff Mode.
 
@@ -4997,8 +5002,8 @@
 
 2005-11-01  Nick Roberts  <nickrob@snap.net.nz>
 
-        * building.texi (Other GDB User Interface Buffers): Describe
-        the command gdb-use-inferior-io-buffer.
+        * building.texi (Other GDB User Interface Buffers):
+        Describe the command gdb-use-inferior-io-buffer.
 
 2005-10-31  Romain Francoise  <romain@orebokech.com>
 
@@ -5036,8 +5041,8 @@
 
 2005-10-25  Nick Roberts  <nickrob@snap.net.nz>
 
-        * building.texi (GDB Graphical Interface): Describe
-        gdb-mouse-until.
+        * building.texi (GDB Graphical Interface):
+        Describe gdb-mouse-until.
 
 2005-10-23  Richard M. Stallman  <rms@gnu.org>
 
@@ -5104,7 +5109,7 @@
 
 2005-10-09  Jan Djärv  <jan.h.d@swipnet.se>
 
-        * cmdargs.texi (Icons X): Removed options -i, -itype, --icon-type,
+        * cmdargs.texi (Icons X): Remove options -i, -itype, --icon-type,
         added -nb, --no-bitmap-icon.
 
 2005-10-07  Nick Roberts  <nickrob@snap.net.nz>
@@ -5141,16 +5146,16 @@
         emulation and related variables.
         (Mac International): Mention Central European and Cyrillic
         support.  Now `keyboard-coding-system' is dynamically changed.
-        Add description about coding system for selection.  Add
-        description about language environment.
-        (Mac Environment Variables): Mention
-        `~/.MacOSX/environment.plist'.  Give example of command line
+        Add description about coding system for selection.
+        Add description about language environment.
+        (Mac Environment Variables):
+        Mention `~/.MacOSX/environment.plist'.  Give example of command line
         arguments.  Add Preferences support.
         (Mac Directories): Explicitly state that this node is for Mac OS
         Classic only.
-        (Mac Font Specs): Mention specification for scalable fonts.  List
-        supported charsets.  Add preferred way of creating fontsets.  Add
-        description about `mac-allow-anti-aliasing'.
+        (Mac Font Specs): Mention specification for scalable fonts.
+        List supported charsets.  Add preferred way of creating fontsets.
+        Add description about `mac-allow-anti-aliasing'.
         (Mac Functions): Add descriptions about `mac-set-file-creator',
         `mac-get-file-creator', `mac-set-file-type', `mac-get-file-type',
         and `mac-get-preference'.
@@ -5312,8 +5317,8 @@
 2005-07-16  Eli Zaretskii  <eliz@gnu.org>
 
         * display.texi (Standard Faces): Explain that customization of
-        `menu' face has no effect on w32 and with GTK.  Add
-        cross-references.
+        `menu' face has no effect on w32 and with GTK.
+        Add cross-references.
 
         * cmdargs.texi (General Variables): Clarify the default location
         of $HOME on w32 systems.
@@ -5325,8 +5330,8 @@
 
 2005-07-08  Kenichi Handa  <handa@m17n.org>
 
-        * mule.texi (Recognize Coding): Recommend
-        revert-buffer-with-coding-system instead of revert-buffer.
+        * mule.texi (Recognize Coding):
+        Recommend revert-buffer-with-coding-system instead of revert-buffer.
 
 2005-07-07  Richard M. Stallman  <rms@gnu.org>
 
@@ -5374,12 +5379,12 @@
 
 2005-06-23  Richard M. Stallman  <rms@gnu.org>
 
-        * anti.texi (Antinews): Renamed show-nonbreak-escape to
+        * anti.texi (Antinews): Rename show-nonbreak-escape to
         nobreak-char-display.
 
         * emacs.texi (Top): Update detailed node listing.
 
-        * display.texi (Text Display): Renamed show-nonbreak-escape
+        * display.texi (Text Display): Rename show-nonbreak-escape
         to nobreak-char-display and no-break-space to nobreak-space.
         (Standard Faces): Split up the list of standard faces
         and put it in a separate node.  Add nobreak-space and
@@ -5391,8 +5396,8 @@
 
 2005-06-23  Kenichi Handa  <handa@m17n.org>
 
-        * mule.texi (International): List all supported scripts.  Adjust
-        text for that leim is now included in the normal Emacs
+        * mule.texi (International): List all supported scripts.
+        Adjust text for that leim is now included in the normal Emacs
         distribution.
         (Language Environments): List all language environments.
         Intlfonts contains fonts for most supported scripts, not all..
@@ -5634,8 +5639,8 @@
 
         * ack.texi (Acknowledgments): Delete info about iso-acc.el.
 
-        * dired.texi (Misc Dired Features): Document
-        dired-compare-directories.
+        * dired.texi (Misc Dired Features):
+        Document dired-compare-directories.
 
         * files.texi (Filesets): New node.
         (File Conveniences): Document Image mode.
@@ -6023,8 +6028,8 @@
 
 2005-03-19  Eli Zaretskii  <eliz@gnu.org>
 
-        * anti.texi (Antinews): Refer to Emacs 21.4, not 21.3.  Update
-        copyright years.
+        * anti.texi (Antinews): Refer to Emacs 21.4, not 21.3.
+        Update copyright years.
 
 2005-03-14  Nick Roberts  <nickrob@snap.net.nz>
 
@@ -6231,7 +6236,7 @@
         (Scrolling): For C-l, don't presume text terminal.
         (Horizontal Scrolling): Simplify intro.
         (Follow Mode): Clarify.
-        (Cursor Display): Moved before Display Custom.
+        (Cursor Display): Move before Display Custom.
         (Display Custom): Explain no-redraw-on-reenter is for text terminals.
         Doc default-tab-width.  Doc line truncation more thoroughly.
 
@@ -6401,8 +6406,8 @@
         cross-references to mailutils documentation.
         Describe various methods of specifying mailbox names,
         user names and user passwords for rmail.
-        (Remote Mailboxes): New section.  Describe
-        how movemail handles remote mailboxes.  Describe configuration
+        (Remote Mailboxes): New section.
+        Describe how movemail handles remote mailboxes.  Describe configuration
         options used to control its behavior.
         (Other Mailbox Formats): Explain handling of various mailbox
         formats.
@@ -6576,8 +6581,8 @@
 2004-11-10  Andre Spiegel  <spiegel@gnu.org>
 
         * files.texi (Version Control): Rewrite the introduction about
-        version systems, mentioning the new ones that we support.  Thanks
-        to Alex Ott, Karl Fogel, Stefan Monnier, and David Kastrup for
+        version systems, mentioning the new ones that we support.
+        Thanks to Alex Ott, Karl Fogel, Stefan Monnier, and David Kastrup for
         suggestions.
 
 2004-11-03  Jan Djärv  <jan.h.d@swipnet.se>
@@ -7072,8 +7077,8 @@
 
 2004-02-21  Juri Linkov  <juri@jurta.org>
 
-        * cmdargs.texi (Action Arguments): Add alias --find-file.  Add
-        --directory, --help, --version.  Move text about command-line-args
+        * cmdargs.texi (Action Arguments): Add alias --find-file.
+        Add --directory, --help, --version.  Move text about command-line-args
         to Command Arguments.
         (Initial Options): Add @cindex for --script.  Fix @cindex for -q.
         Add --no-desktop.  Add alias --no-multibyte, --no-unibyte.
@@ -7093,7 +7098,7 @@
 
 2004-01-24  Richard M. Stallman  <rms@gnu.org>
 
-        * emacs.texi (Acknowledgments): Renamed from Acknowledgements.
+        * emacs.texi (Acknowledgments): Rename from Acknowledgements.
         Include it only @ifnotinfo.  Patch the preceding and following
         node headers to point to each other.
 
@@ -7176,8 +7181,8 @@
 
 2003-09-24  Luc Teirlinck  <teirllm@mail.auburn.edu>
 
-        * cmdargs.texi (Font X): Mention new default font.  More
-        fully describe long font names, wildcard patterns and the
+        * cmdargs.texi (Font X): Mention new default font.
+        More fully describe long font names, wildcard patterns and the
         problems involved.  (Result of discussion on emacs-devel.)
 
 2003-09-22  Luc Teirlinck  <teirllm@mail.auburn.edu>
@@ -7199,8 +7204,8 @@
 
         * screen.texi (Mode Line): Say that POS comes before LINE.
         Mention `size-indication-mode'.
-        * display.texi (Optional Mode Line): Document
-        `size-indication-mode'.
+        * display.texi (Optional Mode Line):
+        Document `size-indication-mode'.
         * basic.texi (Position Info): Mention `size-indication-mode'.
 
 2003-09-07  Luc Teirlinck  <teirllm@mail.auburn.edu>
diff --git a/doc/emacs/maintaining.texi b/doc/emacs/maintaining.texi
index d311104ddd7..bc7484b0557 100644
--- a/doc/emacs/maintaining.texi
+++ b/doc/emacs/maintaining.texi
@@ -744,6 +744,13 @@ is neither visiting a version-controlled file nor a VC directory
 buffer, these commands generate a diff of all registered files in the
 current directory and its subdirectories.
 
+@findex vc-ediff
+The function @code{vc-ediff} works like @code{vc-diff} and provides a way to
+visually compare two revisions of a file an Ediff session, @pxref{Top, Ediff,
+ediff, The Ediff Manual}.  It compares the file associated with the current
+buffer with the last repository revision.  To compare two arbitrary revisions
+of the current file, call @code{vc-ediff} with a prefix argument.
+
 @vindex vc-diff-switches
 @vindex vc-rcs-diff-switches
   @kbd{C-x v =} works by running a variant of the @code{diff} utility